WASHINGTON — Morale has fallen among soldiers in Afghanistan, where troops are seeing record violence in the 8-year-old war, while those in Iraq show much improved mental health amid much lower violence, the Army said Friday. Soldier suicides in Iraq did not increase for the first time since 2004, according to a new study. Though findings of two new battlefield surveys are similar in several ways to the last ones taken in 2007, they come at a time of intense scrutiny on Afghanistan as President Barack Obama struggles to come up with a new war strategy and planned troop buildup.